A sensitive agarose gel electrophoretic technique has been employed for the demonstration of lipoprotein abnormalities in serum samples of normal subjects and patients (1,2). The detection of lipoprotein abnormalities indicated appropriate intervention with therapeutic measures and provided information on the role of lipoproteins in the development of atherosclerotic cardiovascular disease. The same technique was employed to demonstrate that HDL particle isolated by ultracentrifugation is heterogeneous, composed of two lipoprotein electrophoretic fractions, one with alpha and the other with pre-beta mobility (3). This demonstration is of particular importance in view of the opposite roles assigned to those two lipoproteins in the development of atherosclerosis.